Switch from HIDL DisplayCapability to AIDL

In preparation for adding a new DisplayCapability which is only in AIDL.
This change is almost completely mechanical, and should have no impact
on behavior.

Similar to I1f923fcc8d8e6dff388493a76e31d435638b5255 for Composition.

Bug: 193170859
Test: existing tests
Change-Id: I448d5d0ec71f99fb3cbfbe505ded40ab37f6083b
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h b/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
index 0a3437a..69ac26e 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTestHelpers.h
@@ -66,9 +66,9 @@
 using testing::Return;
 using testing::SetArgPointee;
 
+using aidl::android::hardware::graphics::composer3::DisplayCapability;
 using hal::ColorMode;
 using hal::Connection;
-using hal::DisplayCapability;
 using hal::DisplayType;
 using hal::Error;
 using hal::Hdr;